/**
 * i-Darts RAG Chatbot Widget - Embed Loader
 * Lightweight loader script for easy integration
 * Version: 1.0.0
 *
 * Usage:
 * <script src="https://yourserver.com/widget/embed.js"
 *         data-api-url="https://yourserver.com"
 *         data-theme-color="#1e3a8a"
 *         data-welcome-message="Hi! How can I help you?"
 *         data-position="bottom-right">
 * </script>
 */

(function() {
    'use strict';

    console.log('[IDartsWidget] Embed loader started');

    // Get current script element
    const currentScript = document.currentScript || document.querySelector('script[src*="embed.js"]');

    if (!currentScript) {
        console.error('[IDartsWidget] Could not find embed script element');
        return;
    }

    // Read configuration from data attributes
    const config = {
        apiUrl: currentScript.getAttribute('data-api-url') || 'http://localhost:8000',
        themeColor: currentScript.getAttribute('data-theme-color') || '#1e3a8a',
        welcomeMessage: currentScript.getAttribute('data-welcome-message') || 'Hi! How can I help you?',
        position: currentScript.getAttribute('data-position') || 'bottom-right'
    };

    // Get base URL from script src
    const scriptSrc = currentScript.src;
    const baseUrl = scriptSrc.substring(0, scriptSrc.lastIndexOf('/'));

    console.log('[IDartsWidget] Config:', config);
    console.log('[IDartsWidget] Base URL:', baseUrl);

    // Load CSS
    function loadCSS() {
        return new Promise((resolve, reject) => {
            const link = document.createElement('link');
            link.rel = 'stylesheet';
            link.href = `${baseUrl}/chatbot-widget.css`;
            link.onload = () => {
                console.log('[IDartsWidget] CSS loaded');
                resolve();
            };
            link.onerror = () => {
                console.error('[IDartsWidget] Failed to load CSS');
                reject(new Error('Failed to load CSS'));
            };
            document.head.appendChild(link);
        });
    }

    // Load JavaScript
    function loadJS() {
        return new Promise((resolve, reject) => {
            const script = document.createElement('script');
            script.src = `${baseUrl}/chatbot-widget.js`;
            script.async = true;
            script.onload = () => {
                console.log('[IDartsWidget] JavaScript loaded');
                resolve();
            };
            script.onerror = () => {
                console.error('[IDartsWidget] Failed to load JavaScript');
                reject(new Error('Failed to load JavaScript'));
            };
            document.body.appendChild(script);
        });
    }

    // Initialize widget after DOM is ready
    function initWidget() {
        if (typeof window.IDartsChatWidget === 'undefined') {
            console.error('[IDartsWidget] Widget class not found');
            return;
        }

        try {
            window.idartsWidget = new window.IDartsChatWidget(config);
            console.log('[IDartsWidget] Widget initialized successfully');
        } catch (error) {
            console.error('[IDartsWidget] Failed to initialize widget:', error);
        }
    }

    // Load resources and initialize
    function load() {
        Promise.all([loadCSS(), loadJS()])
            .then(() => {
                // Wait for DOM if not ready
                if (document.readyState === 'loading') {
                    document.addEventListener('DOMContentLoaded', initWidget);
                } else {
                    initWidget();
                }
            })
            .catch((error) => {
                console.error('[IDartsWidget] Failed to load widget:', error);
            });
    }

    // Start loading
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', load);
    } else {
        load();
    }

})();